1. Field of the Invention
The present invention relates to a measurement apparatus that has a difference output function for outputting the difference between two measurement results.
2. Description of Related Art
There is disclosed, in Japanese Patent Application Laid-Open Publication No. 2005-106552, a weight scale for weighing a baby. To weigh a baby with this scale, a measurement is taken first of the mother alone, and a second measurement is taken of the mother with the baby, and the difference in weight between the first and the second measurements is output as the baby's weight. This is called a tare weight output function (i.e., difference output function). This weight scale having the tare weight output function holds the data showing the result of the first measurement for a predetermined time period, and only in a case in which the subsequent measurement is taken within the predetermined time period, is the difference in weight between the first and the subsequent measurements obtained and displayed.
However, with the above weight scale having the difference output function, the second measurement must be taken within the predetermined time period. Because it is not allowed to take the second measurement at a time later than the predetermined time period, the time at which the second measurement is taken cannot be freely selected. As a result, the applications of the difference output function are limited, and therefore, a user cannot freely use the difference output function in a way the user wishes.